Lift truck



Jan.,16, 1951 H, J, FRAMHElN 2,538,680

LIFT TRUCK Filed May 11, 1944 2 Sheets-Sheet 1 n s? o I n I g 1n Q3 n D 1.. n u: Ln f." 9 92 n ff 1Q -4x1 "f L\ S E a 4: l' n [wf .su o GO v1 EN; n n n] n v yI wir o o i i 1- 5f A .m im* l i O ..1 l Q FLT f Si lNvENToR ET BY f *Y g ATTORNEY Jan. 156, 1.951 H. J. FRAMHEIN 2,538,680

LIFT TRUCK Filed May 11, 1944 2 Sheets-Sheet 2 ATTORNEY Patented Jan. 16, 1951 UNITED STATES @ENCE 2,538,680 LIFT TRUCK Herbert 5. -Framheim -Chicagm Ill., assigner yto yEhe Yale & Towne Manufacturing Company, Stamford, Conn., a corporation of Connecticut Application May 11, 1944, 'SerialNd 535,019

-4 Claims.

'This vinvention relates to industrial trucks vof the type in which an elevating platform is raised relatively -to a lifting head. More particularly, this invention relatesrto an industrial truck of the 4type 'disclosed vin the Quayle Patent No. 2,274,164. 1It is the Iobject of my invention to improve and simpify the means utilized for lifting the elevating platform of a truck of the particular =c'lass.

In the AQuayle patent the forward end of the elevating "platform is raised by lifting means prog vided for Vthe purpose. The rear end of the elevating platform is elevated by lifting wheels mounted on llifting links that are pivoted to the elevating platform. These lifting links are adapted to lswing downwardly when the forward end of the elevating platform is raised, and thus te eifect-the lifting of the rear end of the elevating platform simultaneously with the elevation of the forward end of the platform. For so actuating the lifting links carrying the lifting wheels, rods extend from said lifting links to mounting links mounting the elevating platform for upward lifting movement relatively to the lifting head of the truck. Thus, it is the swinging movement of the mounting links incidental to the upward movement yof the forward end of the elevating platform, that effects the movement of the rods andthe downward swinging of the lifting links and the lifting wheels.

A feature of my invention resides in the means used by me to actuate the lifting whee's independently of the mounting links or other means mounting the elevating platform for `movement relatively to the lifting head. As a particular feature of this portion of my invention I connect the "lifting links to the lifting head so that movement of the elevating platform relatively to the lifting `head effects the movement of the lifting links relatively to the elevating platform.

As a more particular feature of my invention the lifting links carrying the lifting wheels are directly connected to the lifting head whereby when the elevating platform is moved relatively to the lifting head, the lifting links must necessarily swing downwardly to lift the rear end of the elevating platform.

'The advantages inherent in my invention and certain .additional features thereof, will become more apparent upon a reading of the specification that follows. It will be well to indicate that the general outline of my invention thus far presented will be helpful in the consideration of my invention and its relation to the prior art. However, my invention should not be limited by the g 1 general outline thereof that I 'have -presented,nor to the Adetails of the structure I shall hereinafter set forth, it being obvious that variations and modifications of my invention within the scope of the appended claims will-readily occur yto those skilled in the art.

For a descriptionof 4my invention 'I shall refer to the drawings wherein Fig. 1 Vis a partial-vertical `section rof a truck embodying my invention. Fig. `2 is a partial horizontal section of part of the mechanism shown in Fig. 1. Fig. 3 is aview of certain parts of Fig. 1 showing the elevating platform in its elevated position.

Referring now Ymore particularly to .the drawings, I have show-n my invention applied to a motorized lift truck vof the type illustrated-in my Patent No. 2,327,583. Thus, the lifting head of the truck 'is designated by reference numeral `Il) and carries a battery I I for powering a-motor -un-it housed within the casing I2. The motor unit drives a forward steering and traction wheel I3 that is steered by a steering handle I4, suitable control 'buttons l5 being located on the handle for controlling the motor unit.

The elevating platform shown 'by me is designated generally by reference numeral it, and happens to be of the U type having -twollegs lil. These legs Il are connected by a forwardvertical standard I8 that is pivoted to the lifting "head i9 through lower mounting links I9 and upper mounting links 2li. A hydraulic lifting lassembly 2| is provided, the cylinder of this assembly 2l` being pivoted at 22 to the lifting head 'l0 while the ram portion 23 is pivoted at 2-4 to the elevat ing platform. Upon proper pumping movement of a treadle 25, fluid Yis forced ito the cylinder of the hydraulic lifting assembly 22! and effects the movement of the elevating platform It from its position of Fig. 1 illustrated in the drawings to its position of Fig. 3. The mechanism thus far described is not per se novel in this lapplica-- tion and is well set forth in my applicationsserial No. 493,701, led July 7, 1943, vnow Patent No. 2,417,395 dated March 11, 1947, fora Pallet Truck, and Serial No. 503,745,111ed September I25, 1943, now Patent No. 2,417,396 dated March 11, "1947 for a `Pallet Truck. Those skilled in the art will fully appreciate and understand the Construction of my truck thus far described, and Yit is thought that vno further reference to its structural details is Vhere necessary.

Pivotally carried on each of the legs I1 of the U shaped platform is a lifting link 30 pivoted at 3l and carrying a wheel 32 on an axle 33. Lugs 34 on each link 30 determine the uppermost relation of the links to the legs I1 as is quite apparent. It is the function of the links 30 to swing downwardly as the forward end of the elevating platform is raised, and the Quayle patent and my earlier applications show various means for so doing. I believe that the novel means shown in this application for so swinging the links 30, and presently to be described, mark an important advance and contribution to this art.

A composite adjustable rod is pivoted through shaft 35 directly to each of the links 30, there being of course one rod for each of the legs Il, when a U elevating platform is used. The forward end of each of the composite rods 35 is pivoted about a shaft 31 directly to the lifting head l0, through the intermediary of a con necting sleeve 38, all as is clearly shown in the drawings. A pair of springs 39 are secured at one end through brackets 40 to each U leg Il. At their other ends, springs 39 are secured to each rod 35 and tend to maintain each rod in its position of Fig. 1 with the elevating platform fully lowered.

If the elevating platform I6 is now raised relatively to the lifting head from the position of Fig. l to the position of Fig. 3, it is obvious that the elevating platform i5 will not only be raised, but will be moved rearwardly relatively to the lifting head l0. 'Ihis is clearly indicated in Fig. 3. Since the rods 35 determine the relationship between the lifting head and the rear lifting links 3D, it follows that the links 30 must move downwardly relatively to the elevating platform to the position of Fig. 3, and thereby elevate the rear end of the platform. The springs 39 will of course be extended, and will assist in the lowering of the platform when the hydraulic lifting mechanism 2l is conditioned for lowering movement of the elevating platform. It will now be apparent that through my rods 35 I obtain the lifting of the elevating platform at its rear end without complicating the lower mounting links i9 and without unduly stressing the bearings of the said links.

The rods 35 have been described as composite, and actually each rod is formed of two parts, 35a and 35h, connected through the medium of a turnbuckle 35e. In assembling the truck the elevating platform and lifting head are allowed to assume their position of Fig. l, the turnbuckle 35e acting to adjust the length of each composite rod 35 so that it is of just the right length to perform its function. This is a very valuable feature and greatly facilitates assembly of the truck.

I believe that those skilled in the art will now fully appreciate the construction and operation of my new truck.

I now claim:

l. In a truck of the class described, a lifting head, an elevating platform, upper and lower links pivotally connecting the forward end of the elevating platform to said lifting head for up vward and endwise movement relatively to said lifting head, lifting means for lifting said elevating platform relatively to said lifting head, a lifting link pivoted to the rear of said elevating platform and having a lifting wheel carried thereon, a rod pivotally secured at one end to said lifting link means pivoting the other end of said rod directly on said lifting head, said rod Lil) swinging said link downwardly relatively to said elevating platform as said elevating platform is moved upwardly and endwise by said lifting means relatively to said lifting head.

2. In a truck of the class described, a lifting head, an elevating platform, upper and lower links pivotally connecting the front end of said elevating platform to said lifting head for upward and endwise movement relatively to said lifting head, lifting means for lifting the front end of said elevating platform relatively to said lifting head, a lifting link pivoted to the rear of saidV elevating platform and having a lifting wheel carried thereon, a rod secured at one end to said lifting link and pivoted at its other end directly to said lifting head, said rod swinging said link downwardly relatively to said elevating platform as the front end of said elevating platform is moved upwardly and endwise by said lifting means relatively to said lifting head.

3. In a truck of the class described, a lifting head, an elevating platform, upper and lower links pivotally connecting the front end of said elevating platform to said liftinghead for upward and endwise movement relatively to said lifting head, lifting means for lifting the front end of said elevating platform on said links relatively to said lifting head, a lifting link pivoted to the rear of said elevating platform and having a lifting wheel carried thereon, a rod means pivoting one end directly to said lifting head, and means pivoting the other end of said rod directly to said lifting link, said rod swinging said link downwardly relatively to said elevating platform as said elevating platform is moved upwardly and endwise by said lifting means relatively to said lifting head.

4. In a truck of the class described, a lifting head, an elevating platform, upper and lower links pivotally connecting the forward end of the elevating platform to said lifting head for upward and endwise movement relatively to said lifting head, lifting means for lifting said elevating platform relatively to said lifting head, a lifting link pivoted to the rear of said elevating platform and having a lifting wheel carried` thereon, an adjustable member secured at one end to said lifting link, means pivoting the other.

end of said member directly to said lifting head, said adjustable member swinging said link downwardly relatively to said elevating platform as said elevating platform is moved upwardly and endwise by said lifting means relatively to said lifting head, said adjustable member being adjustable in length so as to secure the lifting link to said lifting head in predetermined relation in any position of said elevating platform relative-v ly to said lifting head.

HERBERT J. FRAMHEIN.

REFERENEES CITED The foilowing references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,077,265 Reed Apr. 13, 1937 2,093,392 Quayle Sept. 14, 1937 2,234,925 Hastings Mar. 11, 1941 2,274,164 Quayle Feb. 24, 1942 2,309,138 Quayle Jan. 26, 1943 

